/*
 * Copyright (c) 1983-2023 Trevor Wishart and Composers Desktop Project Ltd
 * http://www.trevorwishart.co.uk
 * http://www.composersdesktop.com
 *
 This file is part of the CDP System.

    The CDP System is free software; you can redistribute it
    and/or modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    The CDP System is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with the CDP System; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA
 *
 */



/* floatsam version TW */
#include <stdio.h>
#include <stdlib.h>
#include <structures.h>
#include <tkglobals.h>
#include <pnames.h>
#include <globcon.h>
#include <processno.h>
#include <modeno.h>
#include <arrays.h>
#include <flags.h>
#include <highlight.h>
#include <cdpmain.h>
#include <formants.h>
#include <speccon.h>
#include <sfsys.h>
#include <osbind.h>
#include <highlight.h>
//TW UPDATE
#include <vowels.h>

//#ifdef unix 
#define round(x) lround((x))
//#endif

static int  do_filtering(double frq_limit,double hifrq_limit,dataptr dz);
static int  below_limitfrq_and_zeroed(int vc,double loskirt,dataptr dz);
static int  below_limitfrq_and_filtered(int vc,double limitfrq,double loskirt,double loskirt_bwidth,dataptr dz);
static int  above_limitfrq_and_zeroed(int vc,double hiskirt,dataptr dz);
static int  filter_above_limitfrq(int vc,double limitfrq,double hiskirt,double hiskirt_bwidth,dataptr dz);
static int  filtered_in_lower_skirt(int vc,double skirttop,double loskirt,double loskirt_bwidth,dataptr dz);
static int  filtered_in_upper_skirt(int vc,double skirt_bottom,double hiskirt,double hiskirt_bwidth,dataptr dz);
static int  do_greq_filter(dataptr dz);
static int  invert_greq_filter_envelope(dataptr dz);
static int  process_specsplit_channel(int cc,bandptr bb,dataptr dz);
static int  do_on(double bandhilimit,double bandlolimit,dataptr dz);
static int  do_below(double bandmid,dataptr dz);
static int  do_above(double bandmid,dataptr dz);
static int  do_boost(double bandhilimit,double bandlolimit,dataptr dz);
static int  do_above_boost(double bandhilimit,double bandlolimit,int *in_start_portion, dataptr dz);
static int  do_below_boost(double bandhilimit,double bandlolimit,int *in_start_portion,dataptr dz);
static int  do_once_below(double bandlolimit,int *in_start_portion,dataptr dz);
static int  do_once_above(double bandhilimit,int *in_start_portion,dataptr dz);
static int  initiate_new_arpeg_note(int cc,int vc,dataptr dz);
static int  initiate_new_arpeg_note_with_fixed_pitch(int cc,int vc,dataptr dz);
static int  temporarily_sustain_arpeg_note(int cc,double thisamp,dataptr dz);
static int  temporarily_sustain_arpeg_note_with_fixed_pitch(int cc,int vc,double thisamp,dataptr dz);
static int  get_non_linear_decimation(double *nonlin_dec,int cc,dataptr dz);
static int  get_decimation(double *dec,int cc,dataptr dz);
static int  sustain_arpeg_note(int cc,int vc,dataptr dz);
static int  sustain_arpeg_note_with_fixed_pitch(int cc,int vc,dataptr dz);
static int  nonlin_sustain_arpeg_note(int cc,int vc, dataptr dz);
static int  nonlin_sustain_arpeg_note_with_fixed_pitch(int cc, int vc, dataptr dz);
static int  set_bit_to_zero(int bflagno,int mask,dataptr dz);
static int  set_bit_to_one(int bflagno,int mask,dataptr dz);
static int  outside_skirts(int vc,double loskirt,double hiskirt,dataptr dz);
static int  reset_timechanging_arpe_variables(double *frqrange,double *lofrq, double *hifrq,dataptr dz);
static int  locate_current_wavetable_position(dataptr dz);
//TW UPDATE
static int    do_vowel_filter(double *vamp,double formant1,double formant2,double formant3,double f2atten,double f3atten,
                            double *sensitivity,int senslen,dataptr dz);
static int get_formant_frqs
(int vowel,double *formant1, double *formant2, double *formant3, double *f2atten, double *f3atten);
static int define_sensitivity_curve(double **sensitivity,int *senslen);
static int adjust_for_sensitivity(double *amp,double frq,double *sensitivity,int senslen);



/**************************** SPECFILT ***************************/

int specfilt(dataptr dz)
{
    int exit_status;
    int vc;
    double frq_limit, hifrq_limit = 0.0, pre_amptotal, post_amptotal;
    if(dz->brksize[FILT_QQ])
        dz->param[FILT_QQ]   = exp(dz->param[FILT_QQ]);
    if(dz->brksize[FILT_FRQ1])
        frq_limit = exp(dz->param[FILT_FRQ1]);
    else
        frq_limit = dz->param[FILT_FRQ1];
    switch(dz->mode) {
    case(F_BND):
    case(F_BND_NORM):
    case(F_NOTCH):
    case(F_NOTCH_NORM):
    case(F_BAND_GAIN):
    case(F_NOTCH_GAIN):
        if(dz->brksize[FILT_FRQ2])
            hifrq_limit = exp(dz->param[FILT_FRQ2]);
        else
            hifrq_limit = dz->param[FILT_FRQ2];
        if(frq_limit > hifrq_limit)
            swap(&frq_limit,&hifrq_limit);
        break;
    }
    if((exit_status = get_totalamp(&pre_amptotal,dz->flbufptr[0],dz->wanted))<0)
            return(exit_status);
    if((exit_status = do_filtering(frq_limit,hifrq_limit,dz))<0)
        return(exit_status);
    if((exit_status = get_totalamp(&post_amptotal,dz->flbufptr[0],dz->wanted))<0)
            return(exit_status);
    switch(dz->mode) {
    case(F_HI_NORM): 
    case(F_LO_NORM): 
    case(F_BND_NORM): 
    case(F_NOTCH_NORM):   /* normalised output */
        if((exit_status = normalise(pre_amptotal,post_amptotal,dz))<0)
            return(exit_status);
        break;
    case(F_HI_GAIN): 
    case(F_LO_GAIN): 
    case(F_BAND_GAIN): 
    case(F_NOTCH_GAIN): /*  post-gain */
        for(vc = 0; vc < dz->wanted; vc += 2)
            dz->flbufptr[0][AMPP] = (float)(dz->flbufptr[0][AMPP] * dz->param[FILT_PG]);
        break;
    }
    return(FINISHED);
}

/**************************** DO_FILTERING ***************************/

int do_filtering(double frq_limit,double hifrq_limit,dataptr dz)
{
    int exit_status;
    int vc;                                            
    double loskirt, loskirt_bwidth, hiskirt, hiskirt_bwidth;
    switch(dz->mode) {
    case(F_HI): 
    case(F_HI_NORM): 
    case(F_HI_GAIN):
        loskirt        = max(0.0,(frq_limit - dz->param[FILT_QQ]));
        loskirt_bwidth = frq_limit - loskirt;
        for(vc = 0; vc < dz->wanted; vc += 2) {
            if((exit_status = below_limitfrq_and_zeroed(vc,loskirt,dz))<0)
                return(exit_status);
            if(exit_status==TRUE)
                continue;
            if((exit_status = below_limitfrq_and_filtered(vc,frq_limit,loskirt,loskirt_bwidth,dz))<0)
                return(exit_status);
        }           
        break;
    case(F_LO): 
    case(F_LO_NORM): 
    case(F_LO_GAIN):
        hiskirt        = min(dz->nyquist,(frq_limit + dz->param[FILT_QQ]));
        hiskirt_bwidth = hiskirt - frq_limit;
        for(vc = 0; vc < dz->wanted; vc += 2) {
            if((exit_status = above_limitfrq_and_zeroed(vc,hiskirt,dz))<0)
                return(exit_status);
            if(exit_status==TRUE)
                continue;
            if((exit_status = filter_above_limitfrq(vc,frq_limit,hiskirt,hiskirt_bwidth,dz))<0)
                return(exit_status);
        }           
        break;
    case(F_BND): 
    case(F_BND_NORM): 
    case(F_BAND_GAIN):
        loskirt        = max(0.0,(frq_limit - dz->param[FILT_QQ]));
        loskirt_bwidth = frq_limit - loskirt;
        hiskirt        = min(dz->nyquist,(hifrq_limit + dz->param[FILT_QQ]));
        hiskirt_bwidth = hiskirt - hifrq_limit;
        for(vc = 0; vc < dz->wanted; vc += 2) {
            if((exit_status = below_limitfrq_and_zeroed(vc,loskirt,dz))<0)
                return(exit_status);
            if(exit_status==TRUE)
                continue;
            if((exit_status = below_limitfrq_and_filtered(vc,frq_limit,loskirt,loskirt_bwidth,dz))<0)
                return(exit_status);
            if(exit_status == TRUE)     
                continue;
            if((exit_status = above_limitfrq_and_zeroed(vc,hiskirt,dz))<0)
                return(exit_status);
            if(exit_status == TRUE)     
                continue;
            if((exit_status = filter_above_limitfrq(vc,hifrq_limit,hiskirt,hiskirt_bwidth,dz))<0)
                return(exit_status);
        }           
        break;
    case(F_NOTCH): 
    case(F_NOTCH_NORM): 
    case(F_NOTCH_GAIN):
        loskirt        = max(0.0,(frq_limit - dz->param[FILT_QQ]));
        loskirt_bwidth = frq_limit - loskirt;
        hiskirt        = min(dz->nyquist,(hifrq_limit + dz->param[FILT_QQ]));
        hiskirt_bwidth = hiskirt - hifrq_limit;
        for(vc = 0; vc < dz->wanted; vc += 2) {
            if(outside_skirts(vc,loskirt,hiskirt,dz))
                continue;
            if((exit_status = filtered_in_lower_skirt(vc,frq_limit,loskirt,loskirt_bwidth,dz))<0)
                return(exit_status);
            if(exit_status==TRUE)     
                continue;
            if((exit_status = filtered_in_upper_skirt(vc,hifrq_limit,hiskirt,hiskirt_bwidth,dz))<0)
                return(exit_status);
            if(exit_status==TRUE)     
                continue;
            dz->flbufptr[0][AMPP] = 0.0F;
        }           
        break;
    default:
        sprintf(errstr,"unknown mode in do_filtering()\n");
        return(PROGRAM_ERROR);
    }
    return(FINISHED);
}

/**************************** BELOW_LIMITFRQ_AND_ZEROED ***************************/

int below_limitfrq_and_zeroed(int vc,double loskirt,dataptr dz)
{
    if(dz->flbufptr[0][FREQ] < loskirt) {
        dz->flbufptr[0][AMPP] = 0.0F;
        return(TRUE);
    }
    return(FALSE);
}

/**************************** BELOW_LIMITFRQ_AND_FILTERED ***************************/

int below_limitfrq_and_filtered(int vc,double limitfrq,double loskirt,double loskirt_bwidth,dataptr dz)
{
    if(dz->flbufptr[0][FREQ] < limitfrq) {
        dz->flbufptr[0][AMPP] = (float)(dz->flbufptr[0][AMPP] * ((dz->flbufptr[0][FREQ] - loskirt)/loskirt_bwidth));
        return(TRUE);
    }
    return(FALSE);
}

/**************************** FILTER_ABOVE_LIMITFRQ ***************************/

int filter_above_limitfrq(int vc,double limitfrq,double hiskirt,double hiskirt_bwidth,dataptr dz)
{
    if(dz->flbufptr[0][FREQ] > limitfrq) {
        dz->flbufptr[0][AMPP] = (float)(dz->flbufptr[0][AMPP] * ((hiskirt - dz->flbufptr[0][FREQ])/hiskirt_bwidth));
        return(TRUE);
    }
    return(FALSE);
}

/**************************** ABOVE_LIMITFRQ_AND_ZEROED ***************************/

int above_limitfrq_and_zeroed(int vc,double hiskirt,dataptr dz)
{
    if(dz->flbufptr[0][FREQ] > hiskirt) {
        dz->flbufptr[0][AMPP] = 0.0F;
        return(TRUE);
    }
    return(FALSE);
}

/**************************** FILTER_IN_LOWER_SKIRT ***************************/

int filtered_in_lower_skirt(int vc,double skirttop,double loskirt,double loskirt_bwidth,dataptr dz)
{
    if(dz->flbufptr[0][FREQ] < skirttop) {
        dz->flbufptr[0][AMPP] = (float)(dz->flbufptr[0][AMPP] * (1.0 - ((dz->flbufptr[0][FREQ] - loskirt)/loskirt_bwidth)));
        return(TRUE);
    }
    return(FALSE);
}

/**************************** FILTER_IN_UPPER_SKIRT ***************************/

int filtered_in_upper_skirt(int vc,double skirt_bottom,double hiskirt,double hiskirt_bwidth,dataptr dz)
{
    if(dz->flbufptr[0][FREQ] > skirt_bottom) {
        dz->flbufptr[0][AMPP] = (float)(dz->flbufptr[0][AMPP] * (1.0 - ((hiskirt - dz->flbufptr[0][FREQ])/hiskirt_bwidth)));
        return(TRUE);
    }
    return(FALSE);
}

/***********************  SPECGREQ **********************/

int specgreq(dataptr dz)
{
    int exit_status;
    if((exit_status = construct_filter_envelope((int)dz->itemcnt,dz->flbufptr[0],dz))<0)
        return(exit_status);
    if(dz->vflag[GREQ_NOTCH]) {
        if((exit_status = invert_greq_filter_envelope(dz))<0)
            return(exit_status);
    }
    if((exit_status = do_greq_filter(dz))<0)
        return(exit_status);
    return(FINISHED);
}

/****************************** DO_GREQ_FILTER ***************************/

int do_greq_filter(dataptr dz)
{
    int cc, vc;
    for(cc=0, vc=0; cc < dz->clength; cc++, vc += 2)
        dz->flbufptr[0][AMPP] = (float)(dz->flbufptr[0][AMPP] * dz->fsampbuf[cc]);
    return(FINISHED);
}                                                    

/****************************** INVERT_GREQ_FILTER_ENVELOPE ***************************/

int invert_greq_filter_envelope(dataptr dz)
{
    int cc;
    for(cc=0; cc<dz->clength; cc++)
        dz->fsampbuf[cc] = (float)(1.0 - dz->fsampbuf[cc]);
    return(FINISHED);
}   

/******************************** SPECSPLIT ******************************/

int specsplit(dataptr dz) 
{
    int exit_status;
    int cc, bno = 0, bottom, top, done = 0, k;
    bandptr bb;
    double bandbot, bandtop;

    rectify_window(dz->flbufptr[0],dz);
    if((exit_status = get_amp_and_frq(dz->flbufptr[0],dz))<0)
        return(exit_status);        
    cc   = 0;           /* channel counter */
    while(bno<dz->itemcnt) {        /* For all bands */
        bb      = dz->band[bno];
        bandbot = bb->bfrqlo;   
        bandtop = bb->bfrqhi;
        while(dz->freq[cc]<bandbot) {   /* while chan-frq<bandbot: do nothing */
            if(++cc>=dz->clength) {
                done = 1;       
                break;   /* if all channels<bandbot, we.ve finished pass */
            }
        }
        if(done)
            break;
        bottom = cc;        /* set bottom channel for inner loop */
        while(dz->freq[cc]<bandtop) {
            if(++cc>=dz->clength) {
                done = 1;   /* find channels up to top of band */
                break;
            }
        }
        top = min(cc,(dz->clength)-1);  /* set top channel for inner loop */
        if((bb->bdoflag & DO_TRANSPOSITION) && bb->btrans>1.0) {
            for( k = top; k>= bottom; k--) {
                if((exit_status = process_specsplit_channel(k,bb,dz))<0)
                    return(exit_status);
            }
        } else {
            for( k = bottom; k <= top; k++) {
                if((exit_status = process_specsplit_channel(k,bb,dz))<0)
                    return(exit_status);
            }
        }
        if(done)
            break;
        bno++;
    }
    if((exit_status = put_amp_and_frq(dz->flbufptr[0],dz))<0)
        return(exit_status);
    return(FINISHED);
}

/************************ PROCESS_SPECSPLIT_CHANNEL *****************************/

int process_specsplit_channel(int cc,bandptr bb,dataptr dz)
{
    int exit_status;
    double thismult;
    double newamp = dz->amp[cc];    /* DEFAULT */
    double newfrq = dz->freq[cc];   /* DEFAULT */
    int newchan;

    if(bb->bdoflag & DO_AMPLITUDE_CHANGE) {
        if(bb->bdoflag & DO_RAMPED_AMPLITUDE) {
            thismult  = (dz->freq[cc] - bb->bfrqlo)/(bb->bfrqdif);
            thismult *= bb->bampdif;
            thismult += bb->bamp;
            newamp    = dz->amp[cc] * thismult;
        } else
            newamp   = dz->amp[cc] * bb->bamp;
    }
    if(bb->bdoflag & DO_TRANSPOSITION)  {
        if(bb->badditive) {
            if((newfrq  = dz->freq[cc] + bb->btrans)<dz->nyquist) {
                if((exit_status = get_channel_corresponding_to_frq(&newchan,newfrq,dz))<0)
                    return(exit_status);
                if(newchan!=cc) {
                    dz->freq[newchan] = (float)newfrq;
                    dz->amp[newchan]  = (float)newamp;
                }   
            }
        } else {
            if((newfrq  = dz->freq[cc] * bb->btrans)<dz->nyquist) {
                if((exit_status = get_channel_corresponding_to_frq(&newchan,newfrq,dz))<0)
                    return(exit_status);
                if(newchan!=cc) {
                    dz->freq[newchan] = (float)newfrq;
                    dz->amp[newchan]  = (float)newamp;
                }
            }   
        }
        if(!(bb->bdoflag & DO_ADD_TO_SPECTRUM)) {
            newamp =    /* set interpolated value on old amp */
            (dz->amp[max(cc-1,0)] + dz->amp[min(cc+1,(dz->clength-1))])/2.0;
        }
    }
    dz->freq[cc] = (float)newfrq;
    dz->amp[cc]  = (float)newamp;
    return(FINISHED);
}

/********************************** SPECARPE **********************************/

int specarpe(int *in_start_portion,dataptr dz)
{
    int exit_status;
    double  lofrq, hifrq, frqrang;
    double  bandmid, bandhilimit, bandlolimit;
    int     tabindex;
    if((exit_status = reset_timechanging_arpe_variables(&frqrang,&lofrq,&hifrq,dz))<0)
        return(exit_status);        
    if((exit_status = locate_current_wavetable_position(dz))<0)
        return(exit_status);        
    tabindex    = round(dz->param[ARPE_WAVETABPOS]);
                                                    /* LOCATE CURRENT FREQUENCY BAND */
    bandmid     = (dz->parray[ARPE_TAB][tabindex] * frqrang) + lofrq; 
    bandhilimit = min(bandmid + dz->param[ARPE_HBAND],dz->nyquist);
    bandlolimit = max(bandmid - dz->param[ARPE_HBAND],0.0);
      
    if((exit_status = get_amp_and_frq(dz->flbufptr[0],dz))<0)       /* SEPARATE THE AMP AND FREQ DATA */
        return(exit_status);        

    switch(dz->mode) {       /* ELIMINATE OR MODIFY FREQUENCIES, AS NECESSARY */
    case(ON):           exit_status = do_on(bandhilimit,bandlolimit,dz);                            break;
    case(BELOW):        exit_status = do_below(bandmid,dz);                                         break;
    case(ABOVE):        exit_status = do_above(bandmid,dz);                                         break;
    case(BOOST):        exit_status = do_boost(bandhilimit,bandlolimit,dz);                         break;
    case(ABOVE_BOOST):  exit_status = do_above_boost(bandhilimit,bandlolimit,in_start_portion,dz);  break;
    case(BELOW_BOOST):  exit_status = do_below_boost(bandhilimit,bandlolimit,in_start_portion,dz);  break;
    case(ONCE_ABOVE):   exit_status = do_once_above(bandhilimit,in_start_portion,dz);               break;
    case(ONCE_BELOW):   exit_status = do_once_below(bandlolimit,in_start_portion,dz);               break;
    default:
        sprintf(errstr,"unknown mode in specarpe()\n");
        return(PROGRAM_ERROR);
    }
    if(exit_status<0)
        return(exit_status);        

    if((exit_status = put_amp_and_frq(dz->flbufptr[0],dz))<0) /*  WRITE MODIFIED AMP & FREQ BUFF TO SAMP BUFF */
        return(exit_status);        
    return(FINISHED);
}

/*************************** DO_ON ****************************/

int do_on(double bandhilimit,double bandlolimit,dataptr dz)
{
    int exit_status;
    int cc, vc = 0;
    double dec, nonlin_dec = 0.0, thisamp;
    switch(dz->iparam[ARPE_SUSFLAG]) {
    case(AP_NORMAL):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->iparray[ARPE_KEEP][cc]) {
                if((exit_status = sustain_arpeg_note(cc,vc,dz))<0)
                    return(exit_status);
            } else {
                if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                    if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc]  = 0.0f;
            }
        }
        break;
    case(AP_SUSTAIN_PITCH):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->iparray[ARPE_KEEP][cc]) {
                if((exit_status = sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                    return(exit_status);
            } else {
                if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                    if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc]  = 0.0f;
            }
        }
        break;
    case(AP_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = get_decimation(&dec,cc,dz))<0)
                        return(exit_status);
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note(cc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = sustain_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc] = 0.0f;
            }
        }
        break;
    case(AP_SUSTAIN_PITCH_AND_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = get_decimation(&dec,cc,dz))<0)
                    return(exit_status);
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note_with_fixed_pitch(cc,vc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc] = 0.0f;
            }
        }                                       
        break;
    case(AP_NONLIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->iparray[ARPE_KEEP][cc]) {
                if((exit_status = nonlin_sustain_arpeg_note(cc,vc,dz))<0)
                    return(exit_status);
            } else {
                if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                    if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc]  = 0.0f;
            }
        }
        break;
    case(AP_NONLIN_AND_SUSTAIN_PITCH):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->iparray[ARPE_KEEP][cc]) {
                if((exit_status = nonlin_sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                    return(exit_status);
            } else {
                if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                    if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc]  = 0.0f;
            }
        }
        break;
    case(AP_NONLIN_AND_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = get_non_linear_decimation(&nonlin_dec,cc,dz))<0)
                        return(exit_status);
                }
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * nonlin_dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note(cc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = nonlin_sustain_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc] = 0.0f;
            }
        }
        break;
    case(AP_NONLIN_AND_SUSTAIN_PITCH_AND_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = get_non_linear_decimation(&nonlin_dec,cc,dz))<0)
                        return(exit_status);
                }
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * nonlin_dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note_with_fixed_pitch(cc,vc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = nonlin_sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                } else
                    dz->amp[cc] = 0.0f;
            }
        }
        break;
    }
    return(FINISHED);
}


/******************************* DO_BELOW **************************/

int do_below(double bandmid,dataptr dz)
{   
    int cc;
    for(cc=0;cc<dz->clength;cc++) {
        if(dz->freq[cc]>bandmid)
            dz->amp[cc] = 0.0f;
//TW JULY 2006
        else
            dz->amp[cc] = (float)(dz->amp[cc] * dz->param[ARPE_AMPL]);
    }
    return(FINISHED);
}

/******************************** DO_ABOVE ***********************/

int do_above(double bandmid,dataptr dz)
{
    int cc;
    for(cc=0;cc<dz->clength;cc++) {
        if(dz->freq[cc]<bandmid)
            dz->amp[cc] = 0.0f;
//TW JULY 2006
        else
            dz->amp[cc] = (float)(dz->amp[cc] * dz->param[ARPE_AMPL]);
    }
    return(FINISHED);
}

/**************************** DO_BOOST ****************************/

int do_boost(double bandhilimit,double bandlolimit,dataptr dz)
{
    int exit_status;
    int cc, vc;
    double dec, nonlin_dec = 0.0,thisamp;
    switch(dz->iparam[ARPE_SUSFLAG]) {
    case(AP_NORMAL):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->iparray[ARPE_KEEP][cc]) {
                if((exit_status = sustain_arpeg_note(cc,vc,dz))<0)
                    return(exit_status);
            } else if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                    return(exit_status);
            }
        }
        break;
    case(AP_SUSTAIN_PITCH):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->iparray[ARPE_KEEP][cc]) {
                if((exit_status = sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                    return(exit_status);
            } else if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                    return(exit_status);
            }
        }
        break;
    case(AP_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = get_decimation(&dec,cc,dz))<0)
                    return(exit_status);
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note(cc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                     if((exit_status = sustain_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                }
            }
        }
        break;
    case(AP_SUSTAIN_PITCH_AND_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = get_decimation(&dec,cc,dz))<0)
                    return(exit_status);
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note_with_fixed_pitch(cc,vc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                }
            }
        }
        break;
    case(AP_NONLIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if((exit_status = get_non_linear_decimation(&nonlin_dec,cc,dz))<0)
                return(exit_status);
            if(dz->iparray[ARPE_KEEP][cc]) {
                dz->amp[cc] = (float)(dz->windowbuf[0][AMPP] * nonlin_dec);
                dz->iparray[ARPE_KEEP][cc]--;
            } else if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                    return(exit_status);
            }
        }
        break;
    case(AP_NONLIN_AND_SUSTAIN_PITCH):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->iparray[ARPE_KEEP][cc]) {
                if((exit_status = nonlin_sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                    return(exit_status);
            } else if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                    return(exit_status);
            }
        }
        break;
    case(AP_NONLIN_AND_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = get_non_linear_decimation(&nonlin_dec,cc,dz))<0)
                        return(exit_status);
                }
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * nonlin_dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note(cc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                     if((exit_status = nonlin_sustain_arpeg_note(cc,vc,dz))<0)
                        return(exit_status);
                }
            }
        }
        break;
    case(AP_NONLIN_AND_SUSTAIN_PITCH_AND_LIMIT_SUSTAIN):
        for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
            if(dz->freq[cc]>=bandlolimit && dz->freq[cc]<=bandhilimit) {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = get_non_linear_decimation(&nonlin_dec,cc,dz))<0)
                        return(exit_status);
                }
                if(dz->iparray[ARPE_KEEP][cc] && ((thisamp = dz->windowbuf[0][AMPP] * nonlin_dec) > dz->amp[cc])) {
                    if((exit_status = temporarily_sustain_arpeg_note_with_fixed_pitch(cc,vc,thisamp,dz))<0)
                        return(exit_status);
                } else {
                    if((exit_status = initiate_new_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                }
            } else {
                if(dz->iparray[ARPE_KEEP][cc]) {
                    if((exit_status = nonlin_sustain_arpeg_note_with_fixed_pitch(cc,vc,dz))<0)
                        return(exit_status);
                }
            }
        }
        break;
    }
    return(FINISHED);
}

/************************* DO_ABOVE_BOOST ****************************/

int do_above_boost(double bandhilimit,double bandlolimit,int *in_start_portion, dataptr dz)
{
    int cc;   
    if(*in_start_portion) {
        if((dz->iparam[ARPE_WTYPE]==SIN || dz->iparam[ARPE_WTYPE]==SAW)) {
            if(dz->param[ARPE_WAVETABPOS]>=ARPE_TABSIZE/2)
                *in_start_portion = FALSE;
        } else {
            if(dz->param[ARPE_WAVETABPOS] < dz->param[ARPE_LAST_TABPOS])
            *in_start_portion = FALSE;
        }
    }
    if(*in_start_portion) {
        for(cc=0;cc<dz->clength;cc++) {
            if(dz->freq[cc]>bandlolimit)
                dz->amp[cc] = 0.0f;
//TW JULY 2006
            else
                dz->amp[cc] = (float)(dz->amp[cc] * dz->param[ARPE_AMPL] * dz->iparam[ARPE_SUST]);
        }
    } else
        return do_boost(bandhilimit,bandlolimit,dz);
    return(FINISHED);
}

/**************************** DO_BELOW_BOOST ************************/

int do_below_boost(double bandhilimit,double bandlolimit,int *in_start_portion,dataptr dz)
{
    int cc;
    if(*in_start_portion) {
        if(dz->param[ARPE_WAVETABPOS] < dz->param[ARPE_LAST_TABPOS])
            *in_start_portion = FALSE;
    }
    if(*in_start_portion) {
        for(cc=0;cc<dz->clength;cc++) {
            if(dz->freq[cc]<bandhilimit)
                dz->amp[cc] = 0.0f;
//TW JULY 2006
            else
                dz->amp[cc] = (float)(dz->amp[cc] * dz->param[ARPE_AMPL] * dz->iparam[ARPE_SUST]);
        }
    } else
        return do_boost(bandhilimit,bandlolimit,dz);
    return(FINISHED);
}

/************************** DO_ONCE_BELOW ***************************/

int do_once_below(double bandlolimit,int *in_start_portion,dataptr dz)
{
    int cc;
    if(*in_start_portion) {
        if((dz->iparam[ARPE_WTYPE]==SIN || dz->iparam[ARPE_WTYPE]==SAW)) {
            if(dz->param[ARPE_WAVETABPOS] >= ARPE_TABSIZE/2)
                *in_start_portion = FALSE;
        } else {
            if(dz->param[ARPE_WAVETABPOS] < dz->param[ARPE_LAST_TABPOS])
            *in_start_portion = FALSE;
        }
    }
    if(*in_start_portion) {
        for(cc=0;cc<dz->clength;cc++) {
            if(dz->freq[cc]>bandlolimit)
                dz->amp[cc] = 0.0f;
//TW JULY 2006
            else
                dz->amp[cc] = (float)(dz->amp[cc] * dz->param[ARPE_AMPL]);
        }
    }
    return(FINISHED);
}

/***************************** DO_ONCE_ABOVE **************************/

int do_once_above(double bandhilimit,int *in_start_portion,dataptr dz)
{
    int cc;
    if(*in_start_portion) {
        if(dz->param[ARPE_WAVETABPOS] < dz->param[ARPE_LAST_TABPOS])
            *in_start_portion = FALSE;
    }
    if(*in_start_portion) {
        for(cc=0;cc<dz->clength;cc++) {
            if(dz->freq[cc]<bandhilimit)
                dz->amp[cc] = 0.0f;
//TW JULY 2006
            else
                dz->amp[cc] = (float)(dz->amp[cc] * dz->param[ARPE_AMPL]);
        }
    }
    return(FINISHED);
}

/******************** INITIATE_NEW_ARPEG_NOTE ********************/

int initiate_new_arpeg_note(int cc,int vc,dataptr dz)
{
    dz->iparray[ARPE_KEEP][cc] = dz->iparam[ARPE_SUST];
    dz->amp[cc] *= (float)(dz->param[ARPE_AMPL] * dz->iparray[ARPE_KEEP][cc]);
    dz->windowbuf[0][AMPP] = dz->amp[cc];
    (dz->iparray[ARPE_KEEP][cc])--;
    return(FINISHED);
}

/******************** INITIATE_NEW_ARPEG_NOTE_WITH_FIXED_PITCH ********************/

int initiate_new_arpeg_note_with_fixed_pitch(int cc,int vc,dataptr dz)
{
    dz->iparray[ARPE_KEEP][cc] = dz->iparam[ARPE_SUST];
    dz->amp[cc] *= (float)(dz->param[ARPE_AMPL] * dz->iparray[ARPE_KEEP][cc]);
    dz->windowbuf[0][AMPP] = dz->amp[cc];
    dz->windowbuf[0][FREQ] = dz->freq[cc];
    dz->iparray[ARPE_KEEP][cc]--;
    return(FINISHED);
}

/******************** TEMPORARILY_SUSTAIN_ARPEG_NOTE ********************/

int temporarily_sustain_arpeg_note(int cc,double thisamp,dataptr dz)
{
    dz->amp[cc] = (float)thisamp;
    dz->iparray[ARPE_KEEP][cc]--;
    return(FINISHED);
}


/******************** TEMPORARILY_SUSTAIN_ARPEG_NOTE_WITH_FIXED_PITCH ********************/

int temporarily_sustain_arpeg_note_with_fixed_pitch(int cc,int vc,double thisamp,dataptr dz)
{
    dz->amp[cc]  = (float)thisamp;
    dz->freq[cc] = dz->windowbuf[0][FREQ];
    dz->iparray[ARPE_KEEP][cc]--;
    return(FINISHED);
}

/******************** GET_NON_LINEAR_DECIMATION ********************/

int get_non_linear_decimation(double *nonlin_dec,int cc,dataptr dz)
{
    *nonlin_dec = (double)dz->iparray[ARPE_KEEP][cc]/(double)dz->iparam[ARPE_SUST];
    *nonlin_dec = pow(*nonlin_dec,dz->param[ARPE_NONLIN]);
    return(FINISHED);
}

/******************** GET_DECIMATION ********************/

int get_decimation(double *dec,int cc,dataptr dz)
{
    *dec = (double)dz->iparray[ARPE_KEEP][cc]/(double)dz->iparam[ARPE_SUST];
    return(FINISHED);
}

/******************** SUSTAIN_ARPEG_NOTE ********************/

int sustain_arpeg_note(int cc,int vc,dataptr dz)
{
    double z = (double)dz->iparray[ARPE_KEEP][cc]/(double)dz->iparam[ARPE_SUST];
    dz->amp[cc] = (float)(dz->windowbuf[0][AMPP] * z);
    dz->iparray[ARPE_KEEP][cc]--;
    return(FINISHED);
}

/******************** SUSTAIN_ARPEG_NOTE_WITH_FIXED_PITCH ********************/

int sustain_arpeg_note_with_fixed_pitch(int cc,int vc,dataptr dz)
{
    double z = (double)dz->iparray[ARPE_KEEP][cc]/(double)dz->iparam[ARPE_SUST];
    dz->amp[cc] = (float)(dz->windowbuf[0][AMPP] * z);
    dz->freq[cc] = dz->windowbuf[0][FREQ];
    dz->iparray[ARPE_KEEP][cc]--;
    return(FINISHED);
}

/******************** NONLIN_SUSTAIN_ARPEG_NOTE ********************/

int nonlin_sustain_arpeg_note(int cc,int vc, dataptr dz)
{
    double z = (double)dz->iparray[ARPE_KEEP][cc]/(double)dz->iparam[ARPE_SUST];
    z = pow(z,dz->param[ARPE_NONLIN]);
    dz->amp[cc] = (float)(dz->windowbuf[0][AMPP] * z);
    dz->iparray[ARPE_KEEP][cc]--;
    return(FINISHED);
}

/******************** NONLIN_SUSTAIN_ARPEG_NOTE_WITH_FIXED_PITCH ********************/

int nonlin_sustain_arpeg_note_with_fixed_pitch(int cc, int vc, dataptr dz)
{
    double z = (double)dz->iparray[ARPE_KEEP][cc]/(double)dz->iparam[ARPE_SUST];
    z = pow(z,dz->param[ARPE_NONLIN]);
    dz->amp[cc]  = (float)(dz->windowbuf[0][AMPP] * z);
    dz->freq[cc] = dz->windowbuf[0][FREQ];
    dz->iparray[ARPE_KEEP][cc]--;
    return(FINISHED);
}

/****************************** SPECPLUCK ****************************/

int specpluck(dataptr dz)
{
    int exit_status;
    int mask = 1;
    int cc, vc, bflagno, is_set;
    if(dz->total_windows==1) {      /* Set up BITFLAGS for current state of chans */
        for(cc = 0, vc = 0; cc < dz->clength; cc++, vc += 2){
            if((exit_status = choose_bflagno_and_reset_mask_if_ness
            (&bflagno,cc,&mask,dz->iparam[PLUK_LONGPOW2],dz->iparam[PLUK_DIVMASK]))<0)
                return(exit_status);
            if(!flteq((double)dz->flbufptr[0][AMPP],0.0))
                dz->lparray[PLUK_BFLG][bflagno] |= mask;
            mask <<= 1;         
        }
    } else {                    /* Check change of state of channels */
        for(cc = 0, vc = 0; cc < dz->clength; cc++, vc += 2){
            if((exit_status = choose_bflagno_and_reset_mask_if_ness
            (&bflagno,cc,&mask,dz->iparam[PLUK_LONGPOW2],dz->iparam[PLUK_DIVMASK]))<0)
                return(exit_status);
            is_set = dz->lparray[PLUK_BFLG][bflagno] & mask;
            if(!flteq((double)dz->flbufptr[0][vc],0.0)) {   /* If chan amp NOT zero */
                if(!is_set) {                       /* if bit previously 0 (for zero amp) */
                    dz->flbufptr[0][vc] = (float)(dz->flbufptr[0][vc] * dz->param[PLUK_GAIN]);
                    exit_status = set_bit_to_one(bflagno,mask,dz);     /* Give boost to chan amp */
                }
            } else {                                /* channel amp IS zero */
                if(is_set)                          /* if bit previously 1 for nonzero amp */
                    exit_status = set_bit_to_zero(bflagno,mask,dz);
            }
            mask <<= 1;                             /* move bitmask upwards */
        }
    }       
    return(FINISHED);
}

/****************************** SET_BIT_TO_ZERO ****************************/

int set_bit_to_zero(int bflagno,int mask,dataptr dz)
{
    mask = ~mask;                             /* bit-invert mask */
    dz->lparray[PLUK_BFLG][bflagno] &= mask;  /* Set bit to 0 */
    return(FINISHED);
}


/****************************** SET_BIT_TO_ONE ****************************/

int set_bit_to_one(int bflagno,int mask,dataptr dz)
{
    dz->lparray[PLUK_BFLG][bflagno] |= mask;  
    return(FINISHED);
}

/********************************** SPECTRACE **********************************/

int spectrace(dataptr dz)
{
    int exit_status;
    int invtrindex, cc, vc;
    int    chans_outside_fltband_to_keep = 0, chans_in_filtband;
    double  hifrq_limit = 0.0, lofrq_limit = 0.0;
    chvptr quietest, loudest;
    if((dz->mode == TRC_ALL || dz->vflag[TRACE_RETAIN]) && dz->iparam[TRAC_INDX] >= dz->clength)
        return(FINISHED);
    if(dz->mode != TRC_ALL) {
        hifrq_limit = dz->param[TRAC_HIFRQ];
        lofrq_limit = dz->param[TRAC_LOFRQ];
        if(hifrq_limit < lofrq_limit)
            swap(&hifrq_limit,&lofrq_limit);
        if(dz->vflag[TRACE_RETAIN] ) {
            chans_in_filtband = dz->clength;
            for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
                if(dz->flbufptr[0][FREQ] < lofrq_limit || dz->flbufptr[0][FREQ] > hifrq_limit)
                    chans_in_filtband--;
            }
            if((chans_outside_fltband_to_keep = dz->iparam[TRAC_INDX] - chans_in_filtband) <= 0) {
                chans_outside_fltband_to_keep = 0;
                for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
                    if(dz->flbufptr[0][FREQ] < lofrq_limit || dz->flbufptr[0][FREQ] > hifrq_limit)
                        dz->flbufptr[0][AMPP] = 0.0f;
                }
            }
        } else {
            for(cc=0,vc=0;cc<dz->clength;cc++,vc+=2) {
                if(dz->flbufptr[0][FREQ] < lofrq_limit || dz->flbufptr[0][FREQ] > hifrq_limit)
                    dz->flbufptr[0][AMPP] = 0.0f;
            }
        }
    }
    if(chans_outside_fltband_to_keep>0) {
        if((exit_status = initialise_ring_vals(chans_outside_fltband_to_keep,-BIGAMP,dz))<0)
            return(exit_status);
        for(vc = 0; vc < dz->wanted; vc += 2) {
            if(dz->flbufptr[0][FREQ] < lofrq_limit || dz->flbufptr[0][FREQ] > hifrq_limit) {
                if((exit_status = if_one_of_loudest_chans_store_in_ring(vc,dz))<0)
                    return(exit_status);
                dz->flbufptr[0][AMPP]  = 0.0F;
            }
        }
     /* RESTORE TRUE AMPLITUDE (STORED IN RING) IN LOUDEST OUTSIDER CHANNELS ONLY */
        loudest = dz->ringhead;     
        do {
            dz->flbufptr[0][loudest->loc] = loudest->val;
        } while((loudest = loudest->next)!=dz->ringhead);
    } else {
        if(dz->iparam[TRAC_INDX]>(dz->clength/2)) {                         /* IF MORE CHANS TO KEEP THAN TO REJECT */
            invtrindex = dz->clength - dz->iparam[TRAC_INDX];               /* COUNT CHANS TO REJECT */
            if((exit_status = initialise_ring_vals(invtrindex,BIGAMP,dz))<0)/* MAXIMISE ALL QUIETEST STORES IN RING */
                return(exit_status);
            for(vc = 0; vc < dz->wanted; vc += 2) {                         /* STORE INDICES OF QUIETEST CHANS */
                if((exit_status = if_one_of_quietest_chans_store_in_ring(vc,dz))<0)
                    return(exit_status);
            }
            quietest = dz->ringhead;        
            do {                                                            /* ZERO ALL QUIETEST CHANS */
                dz->flbufptr[0][quietest->loc] = 0.0F;
            } while((quietest = quietest->next)!=dz->ringhead);
        } else {                                                            /* IF MORE CHANS TO REJECT THAN TO KEEP */
            if((exit_status = initialise_ring_vals(dz->iparam[TRAC_INDX],-BIGAMP,dz))<0)
                return(exit_status);                                        /* MINIMISE ALL LOUDEST STORES IN RING */
            for(vc = 0; vc < dz->wanted; vc += 2) {
                if((exit_status = if_one_of_loudest_chans_store_in_ring(vc,dz))<0)
                    return(exit_status);                                    /* STORE INDICES OF LOUDEST CHANS */
                dz->flbufptr[0][AMPP]  = 0.0F;                              /* INITIALISE EVERY CHANNEL TO ZERO AMP  */
            }
            loudest = dz->ringhead;             
            do {                                                            /* RESTORE AMPLITUDE IN LOUDEST CHANS ONLY */
                dz->flbufptr[0][loudest->loc] = loudest->val;
            } while((loudest = loudest->next)!=dz->ringhead);
        }
    }
    return(FINISHED);
}

/**************************** OUTSIDE_SKIRTS ***************************/

int outside_skirts(int vc,double loskirt,double hiskirt,dataptr dz)
{
    if(dz->flbufptr[0][FREQ] < loskirt || dz->flbufptr[0][FREQ] > hiskirt)
        return(TRUE);
    return(FALSE);
}

/***************************** RESET_TIMECHANGING_ARPE_VARIABLES **************************/

int reset_timechanging_arpe_variables(double *frqrange,double *lofrq, double *hifrq,dataptr dz)
{
    double this_arpfrq;

    if(dz->brksize[ARPE_ARPFRQ]) {                /* RESET ARPFREQ, if ness */
        this_arpfrq = (dz->param[ARPE_LASTARPFRQ] + dz->param[ARPE_ARPFRQ])/2.0;
        dz->param[ARPE_LASTARPFRQ] = dz->param[ARPE_ARPFRQ];
        dz->param[ARPE_ARPFRQ] = this_arpfrq;
    }
                                                  /* RESET arp amplification, if ness */
//TW JULY 2006
    if(dz->mode < BELOW) {
        if(dz->brksize[ARPE_AMPL] || dz->brksize[ARPE_SUST])
            dz->param[ARPE_AMPL]  /= (double)dz->iparam[ARPE_SUST];
    }

    *lofrq = dz->param[ARPE_LOFRQ];               /* RESET arp hi and lo limits */
    *hifrq = dz->param[ARPE_HIFRQ];
    if((dz->brksize[ARPE_LOFRQ] || dz->brksize[ARPE_HIFRQ])
    && (*hifrq < *lofrq))
        swap(hifrq,lofrq);
    *frqrange = *hifrq - *lofrq;

    return(FINISHED);
}                                                   

/******************** LOCATE_CURRENT_WAVETABLE_POSITION ********************/

int locate_current_wavetable_position(dataptr dz)
{                                                   
    double tabincr;
    tabincr                     = dz->frametime * dz->param[ARPE_ARPFRQ] * ARPE_TABSIZE;
    dz->param[ARPE_LAST_TABPOS] = dz->param[ARPE_WAVETABPOS];
    dz->param[ARPE_WAVETABPOS]  = fmod(dz->param[ARPE_WAVETABPOS] + tabincr,(double)ARPE_TABSIZE);
    return(FINISHED);
}

//TW UPDATE: NEW FUNCTIONS (adjusted for float)
/************************************ VOWEL_FILTER ************************************/

#define NOISEBASE   (0.2)

int vowel_filter(dataptr dz)
{
    int *vowels = dz->iparray[0];
    double *times = dz->parray[0];
    double startformant1, startformant2, startformant3, endformant1, endformant2, endformant3;
    double formant1, formant2, formant3;
    double form1step, form2step, form3step;
    double starttime, endtime, time, timefrac, timestep, *sensitivity;
    double f3startatten, f3endatten, f3attenstep, f3atten;
    double f2startatten, f2endatten, f2attenstep, f2atten;
    int exit_status, senslen;
    int n = 0, t = 0;
    double *amp;
    int total_windows_got, windows_in_buf;

    if((amp = (double *)malloc(dz->clength * sizeof(double)))==NULL) {
        sprintf(errstr,"Insufficient memory to store vowel envelope\n");
        return(MEMORY_ERROR);
    }
    if((exit_status = define_sensitivity_curve(&sensitivity,&senslen))<0)
        return(exit_status);

    dz->flbufptr[0] = dz->bigfbuf;
    if((exit_status = get_formant_frqs
    (vowels[t],&startformant1,&startformant2,&startformant3,&f2startatten,&f3startatten))<0)
        return(exit_status);
    starttime = times[t++];
    if((exit_status = get_formant_frqs(vowels[t],&endformant1,&endformant2,&endformant3,&f2endatten,&f3endatten))<0)
        return(exit_status);
    endtime = times[t++];
    form1step = endformant1 - startformant1;
    form2step = endformant2 - startformant2;
    form3step = endformant3 - startformant3;
    f2attenstep = f2endatten - f2startatten; 
    f3attenstep = f3endatten - f3startatten; 
    timestep  = endtime-starttime;
    formant1 = startformant1;   /* works if only one vowel is entered (for time zero) */
    formant2 = startformant2;
    formant3 = startformant3;
    f2atten  = f2startatten;
    f3atten  = f3startatten;

    total_windows_got = 0;

    while(n < dz->wlength) {
        if(n >= total_windows_got) {
            if((exit_status = read_samps(dz->bigfbuf, dz)) < 0) {
                sprintf(errstr,"Problem reading source analysis data.\n");
                return(SYSTEM_ERROR);
            }
            dz->flbufptr[0] = dz->bigfbuf;
            windows_in_buf = dz->ssampsread/dz->wanted;
            total_windows_got += windows_in_buf;
        }
        if(dz->itemcnt) {
            time = n * dz->frametime;
            while(time >= endtime) {        /* advance along vowels */
                startformant1 = endformant1;
                startformant2 = endformant2;
                startformant3 = endformant3;
                f2startatten  = f2endatten;
                f3startatten  = f3endatten;
                starttime = endtime;
                if(t < dz->itemcnt) {
                    if((exit_status = get_formant_frqs(vowels[t],&endformant1,&endformant2,&endformant3,&f2endatten,&f3endatten))<0)
                        return(exit_status);
                    endtime = times[t++];
                } else
                    break;
                form1step = endformant1 - startformant1;
                form2step = endformant2 - startformant2;
                form3step = endformant3 - startformant3;
                f2attenstep = f2endatten - f2startatten; 
                f3attenstep = f3endatten - f3startatten; 
                timestep  = endtime-starttime;
            }
            if(!flteq(starttime,endtime)) {                 /* interpolate between vowels : or retain last vowel */
                timefrac = (time - starttime)/timestep;
                formant1 = startformant1 + (form1step * timefrac);
                formant2 = startformant2 + (form2step * timefrac);
                formant3 = startformant3 + (form3step * timefrac);
                f2atten  = f2startatten  + (f2attenstep * timefrac);
                f3atten  = f3startatten  + (f3attenstep * timefrac);
            }
        }
        if((exit_status = do_vowel_filter
        (amp,formant1,formant2,formant3,f2atten,f3atten,sensitivity,senslen,dz)) <0)
            return(exit_status);

        if((dz->flbufptr[0] += dz->wanted) >= dz->flbufptr[1]) {
            if((exit_status = write_samps(dz->bigfbuf,dz->buflen,dz))<0)
                return(exit_status);
            dz->flbufptr[0] = dz->bigfbuf;
        }
        n++;
    }
    if(dz->flbufptr[0] != dz->bigfbuf) {
        if((exit_status = write_samps(dz->bigfbuf,dz->flbufptr[0] - dz->bigfbuf,dz))<0)
            return(exit_status);
    }
    return(FINISHED);
}
        
/************************************ DO_VOWEL_FILTER ************************************
 *
 * "sensitivity" compensates for frq sensitivity of ear at low end, and attenuates
 * formant bands above c3500.
 */

int do_vowel_filter(double *vamp,double formant1,double formant2,double formant3,double f2atten,double f3atten,
                            double *sensitivity,int senslen,dataptr dz)

{
    double hfwidth1, hfwidth2, hfwidth3 = 0.0, lolim1, lolim2, lolim3 = 0.0, hilim1, hilim2, hilim3 = 0.0;
//  double thisfrq, amp, amp2, amp3 = 0.0, totamp = 0.0;
    double thisfrq, amp, amp2 = 0.0, amp3 = 0.0;
    int exit_status, cc, vc;
    int overlapped_formants12 = 0, overlapped_formants23 = 0, overlapped_formants13 = 0;
    int is_overlap12, is_overlap23, is_overlap13;
    double /*toplim,*/ pre_totamp, post_totamp, maxamp, maxvamp, ampscale;
    int is_third_formant = 0;
    double signal_base = 1.0 - dz->param[PV_PKRANG];

    if(formant3 > 0.0)
        is_third_formant = 1;
    hfwidth1 = formant1 * dz->param[PV_HWIDTH]; /* set limits of formant bands */
    lolim1  = formant1 - hfwidth1;
    hilim1  = formant1 + hfwidth1;
    hfwidth2 = formant2 * dz->param[PV_HWIDTH];
    lolim2  = formant2 - hfwidth2;
    hilim2  = formant2 + hfwidth2;
    if(is_third_formant) {
        hfwidth3 = formant3 * dz->param[PV_HWIDTH];
        lolim3  = formant3 - hfwidth3;
        hilim3  = formant3 + hfwidth3;
    }

    if(hilim1 > lolim2)     /* deal with overlapping formants */
        overlapped_formants12 = 1;
    if(is_third_formant) {
        if(hilim2 > lolim3)
            overlapped_formants23 = 1;
        if(hilim1 > lolim3)
            overlapped_formants13 = 1;
    }
//    if(is_third_formant)
//        toplim =  hilim3;
//    else
//        toplim =  hilim2;
    maxamp = 0.0;
    pre_totamp = 0.0;
    for(cc = 0, vc = 0; cc < dz->clength; cc++, vc += 2) {
        pre_totamp += dz->flbufptr[0][AMPP];
        maxamp = max(dz->flbufptr[0][AMPP],maxamp);     
    }
    maxvamp = 0.0;
    /* find the formant envelope amplitude at frequency of every window */
    if(!is_third_formant)
        hilim3 = hilim2;
    for(cc = 0, vc = 0;cc <dz->clength; cc++, vc += 2) {
        thisfrq = dz->flbufptr[0][FREQ];
        amp = 0.0;
        is_overlap12 = 0;
        is_overlap23 = 0;
        is_overlap13 = 0;
        if(thisfrq < lolim1 || thisfrq > hilim3)
            ;
        else if((thisfrq > lolim1) && (thisfrq < hilim1)) {
            if(overlapped_formants12 && (thisfrq > lolim2)) {
                is_overlap12 = 1;
                if(thisfrq >= formant2)
                    amp2 = (hilim2 - thisfrq)/hfwidth2;
                else
                    amp2 = (thisfrq - lolim2)/hfwidth2;
                amp2 *= f2atten;
            }
            if(is_third_formant) {
                if(overlapped_formants13 && (thisfrq > lolim3)) {
                    is_overlap13 = 1;
                    if(thisfrq >= formant3)
                        amp3 = (hilim3 - thisfrq)/hfwidth3;
                    else
                        amp3 = (thisfrq - lolim3)/hfwidth3;
                    amp3 *= f3atten;
                }
            }
            if(thisfrq >= formant1)
                amp = (hilim1 - thisfrq)/hfwidth1;
            else
                amp = (thisfrq - lolim1)/hfwidth1;
            if(is_overlap12)
                amp = max(amp,amp2);
            if(is_third_formant && is_overlap13)
                amp = max(amp,amp3);
        } else if((thisfrq > lolim2) && (thisfrq < hilim2)) {
            if(is_third_formant && overlapped_formants23 && (thisfrq > lolim3)) {
                is_overlap23 = 1;
                if(thisfrq >= formant3)
                    amp3 = (hilim3 - thisfrq)/hfwidth3;
                else
                    amp3 = (thisfrq - lolim3)/hfwidth3;
                amp3 *= f3atten;
            }
            if(thisfrq >= formant2)
                amp = (hilim2 - thisfrq)/hfwidth2;
            else
                amp = (thisfrq - lolim2)/hfwidth2;
            amp *= f2atten;

            if(is_third_formant && is_overlap23)
                amp = max(amp,amp3);
        } else if(is_third_formant && (thisfrq > lolim3)) {
            if(thisfrq >= formant3)
                amp = (hilim3 - thisfrq)/hfwidth3;
            else
                amp = (thisfrq - lolim3)/hfwidth3;
            amp *= f3atten;
        }
        amp = pow(amp,dz->param[PV_CURVIT]);
        amp *= dz->param[PV_PKRANG];
        amp += signal_base;
        if((exit_status = adjust_for_sensitivity(&amp,(double)thisfrq,sensitivity,senslen))<0)
            return(exit_status);
        vamp[cc] = amp;
        maxvamp = max(maxvamp,vamp[cc]);
    }
    /* set scaling factor to allow for max level of input window */
    if(flteq(maxvamp,0.0))
        ampscale = 0.0;
    else
        ampscale = (maxamp/maxvamp);
    post_totamp = 0.0;
    for(cc = 0,vc = 0;cc <dz->clength; cc++,vc += 2) {
        vamp[cc] *= ampscale;
/* force window to formant level ONLY if existing val > a given proportion of formant level */
        if((double)dz->flbufptr[0][AMPP] > vamp[cc] * dz->param[VF_THRESH])
            dz->flbufptr[0][AMPP] =  (float)vamp[cc];
        post_totamp += dz->flbufptr[0][AMPP];
    }
/* normalise to overall level of original window */
    if((exit_status = normalise(pre_totamp,post_totamp,dz))<0)
        return(exit_status);
    return(FINISHED);
}

/************************************ DEFINE_SENSITIVITY_CURVE ************************************
 *
 * approximate compensation for aural sensitivity 
 */

#define LOFRQ_BOOST     (2.511)     /* 8dB  */
#define HIFRQ_LOSS      (0.4)       /* -8dB */

#define LOFRQ_FOOT      (250.0)
#define MIDFRQSHELF_BOT (2000.0)
#define MIDFRQSHELF_TOP (3000.0)
#define HIFRQ_FOOT      (4000.0)
#define TOP_OF_SPECTRUM (96000.0)   /* double maximum nyquist (i.e. >nyquist: for safety margin)  */

int define_sensitivity_curve(double **sensitivity,int *senslen)
{
    int arraysize = BIGARRAY;
    double *p;
    int n = 0;
    if((*sensitivity = (double *)malloc(arraysize * sizeof(double)))==NULL) {
        sprintf(errstr,"INSUFFICIENT MEMORY for time data.\n");
        return(MEMORY_ERROR);
    }
    p = *sensitivity;
    *p++ = 0.0;             *p++ = 1.0;                     n+= 2;  /* everything must be in 0-1 range */
    *p++ = LOFRQ_FOOT;      *p++ = 1.0;                     n+= 2;  /* for pow() calculations to work, later */
    *p++ = MIDFRQSHELF_BOT; *p++ = 1.0/LOFRQ_BOOST;         n+= 2;
    *p++ = MIDFRQSHELF_TOP; *p++ = 1.0/LOFRQ_BOOST;         n+= 2;
    *p++ = HIFRQ_FOOT;      *p++ = HIFRQ_LOSS/LOFRQ_BOOST;  n+= 2;
    *p++ = TOP_OF_SPECTRUM; *p++ = HIFRQ_LOSS/LOFRQ_BOOST;  n+= 2;

    if((*sensitivity = (double *)realloc((char *)(*sensitivity),n * sizeof(double)))==NULL) {
        sprintf(errstr,"INSUFFICIENT MEMORY for sensitivity curve.\n");
        return(MEMORY_ERROR);
    }
    *senslen = n;
    return(FINISHED);
}

/************************************ GET_FORMANT_FRQS ************************************/

int get_formant_frqs
(int vowel,double *formant1, double *formant2, double *formant3, double *f2atten, double *f3atten)
{
    switch(vowel) {
    case(VOWEL_EE): *formant1= EE_FORMANT1; *formant2= EE_FORMANT2; *formant3= EE_FORMANT3; 
    /* heed  */                             *f2atten = EE_F2ATTEN;  *f3atten = EE_F3ATTEN;
                    break;
    case(VOWEL_I):  *formant1= I_FORMANT1;  *formant2= I_FORMANT2;  *formant3= I_FORMANT3;
    /* hid  */                              *f2atten = I_F2ATTEN;   *f3atten = I_F3ATTEN;
                    break;
    case(VOWEL_AI): *formant1= AI_FORMANT1; *formant2= AI_FORMANT2; *formant3= AI_FORMANT3; 
    /* maid  */                             *f2atten = AI_F2ATTEN;  *f3atten = AI_F3ATTEN;
                    break;
    case(VOWEL_AII): *formant1= AII_FORMANT1;   *formant2= AII_FORMANT2;    *formant3= AII_FORMANT3;    
    /* scottish educAted  */                *f2atten = AII_F2ATTEN; *f3atten = AII_F3ATTEN;
                    break;
    case(VOWEL_E):  *formant1= E_FORMANT1;  *formant2= E_FORMANT2;  *formant3= E_FORMANT3;  
    /* head  */                             *f2atten = E_F2ATTEN;   *f3atten = E_F3ATTEN;
                    break;
    case(VOWEL_A):  *formant1= A_FORMANT1;  *formant2= A_FORMANT2;  *formant3= A_FORMANT3;  
    /* had  */                              *f2atten = A_F2ATTEN;   *f3atten = A_F3ATTEN;
                    break;
    case(VOWEL_AR): *formant1= AR_FORMANT1; *formant2= AR_FORMANT2; *formant3= AR_FORMANT3; 
    /* hard  */                             *f2atten = AR_F2ATTEN;  *f3atten = AR_F3ATTEN;
                    break;
    case(VOWEL_O):  *formant1= O_FORMANT1;  *formant2= O_FORMANT2;  *formant3= O_FORMANT3;  
    /* hod  */                              *f2atten = O_F2ATTEN;   *f3atten = O_F3ATTEN;
                    break;
    case(VOWEL_OR): *formant1= OR_FORMANT1; *formant2= OR_FORMANT2; *formant3= OR_FORMANT3; 
    /* hoard  */                            *f2atten = OR_F2ATTEN;  *f3atten = OR_F3ATTEN;
                    break;
    case(VOWEL_OA): *formant1= OA_FORMANT1; *formant2= OA_FORMANT2; *formant3= OA_FORMANT3; 
    /* load (North of England)  */          *f2atten = OA_F2ATTEN;  *f3atten = OA_F3ATTEN;
                    break;
    case(VOWEL_U):  *formant1= U_FORMANT1;  *formant2= U_FORMANT2;  *formant3= U_FORMANT3;  
    /* hood, mud (North of England)  */     *f2atten = U_F2ATTEN;   *f3atten = U_F3ATTEN;
                    break;
    case(VOWEL_UU): *formant1= UU_FORMANT1; *formant2= UU_FORMANT2; *formant3= UU_FORMANT3; 
    /* Scottish edUcated  */                *f2atten = UU_F2ATTEN;  *f3atten = UU_F3ATTEN;
                    break;
    case(VOWEL_UI): *formant1= UI_FORMANT1; *formant2= UI_FORMANT2; *formant3= UI_FORMANT3; 
    /* Scottish 'could'  */                 *f2atten = UI_F2ATTEN;  *f3atten = UI_F3ATTEN;
                    break;
    case(VOWEL_OO): *formant1= OO_FORMANT1; *formant2= OO_FORMANT2; *formant3= OO_FORMANT3; 
    /* mood  */                             *f2atten = OO_F2ATTEN;  *f3atten = OO_F3ATTEN;
                    break;
    case(VOWEL_XX): *formant1= XX_FORMANT1; *formant2= XX_FORMANT2; *formant3= XX_FORMANT3; 
    /* mud (South of England)  */           *f2atten = XX_F2ATTEN;  *f3atten = XX_F3ATTEN;
                    break;
    case(VOWEL_X):  *formant1= X_FORMANT1;  *formant2= X_FORMANT2;  *formant3 = X_FORMANT3; 
    /* the, herd  */                        *f2atten = X_F2ATTEN;   *f3atten = X_F3ATTEN;
                    break;
    case(VOWEL_N):  *formant1= N_FORMANT1;  *formant2= N_FORMANT2;  *formant3 = N_FORMANT3; 
    /* 'n'  */                              *f2atten = N_F2ATTEN;   *f3atten = N_F3ATTEN;
                    break;
    case(VOWEL_M):  *formant1= M_FORMANT1;  *formant2= M_FORMANT2;  *formant3 = M_FORMANT3; 
    /* 'm' */                               *f2atten = M_F2ATTEN;   *f3atten = M_F3ATTEN;
                    break;
    case(VOWEL_R):  *formant1= R_FORMANT1;  *formant2= R_FORMANT2;  *formant3 = R_FORMANT3; 
    /* dRaws  */                            *f2atten = R_F2ATTEN;   *f3atten = R_F3ATTEN;
                    break;
    case(VOWEL_TH): *formant1= TH_FORMANT1; *formant2= TH_FORMANT2; *formant3 = TH_FORMANT3;    
    /* 'THe'  */                            *f2atten = TH_F2ATTEN;  *f3atten = TH_F3ATTEN;
                    break;
    default:
        sprintf(errstr,"Unknown vowel\n");
        return(PROGRAM_ERROR);
    }
    return(FINISHED);
}

/************************************ ADJUST_FOR_SENSITIVITY ************************************/

int adjust_for_sensitivity(double *amp,double frq,double *sensitivity,int senslen)
{
    int n = 0;
    double multiplier, losensfrq, hisensfrq, losens, hisens, frqfrac, sensstep;

    while(frq > sensitivity[n]) {
        n += 2;
        if(n > senslen) {
            sprintf(errstr,"Failed to find sensitivity value (1)\n");
            return(PROGRAM_ERROR);
        }
    }
    hisensfrq = sensitivity[n]; 
    n -= 2;
    if(n < 0) {
        *amp *= sensitivity[1];
        return(FINISHED);
    }
    losensfrq = sensitivity[n]; 
    frqfrac = (frq - losensfrq)/(hisensfrq - losensfrq);
    n++;
    losens = sensitivity[n];
    n += 2;
    if(n >= senslen) {
        sprintf(errstr,"Failed to find sensitivity value (3)\n");
        return(PROGRAM_ERROR);
    }
    hisens = sensitivity[n];
    sensstep = hisens - losens;

    multiplier = losens + (sensstep * frqfrac);
    *amp *= multiplier;
    return(FINISHED);
}

